A large variety of polish formulations intended for polishing floor surfaces is known in the art. These polish formulations usually contain mainly resins, surfactants, plasticizers, coalescents, solvents, fragrances and water.
Those formulations are supposed to provide gloss, mechanical strength and resistance to spots (low water absorption) to the floor. Those properties are linked with a good film formation, which is reached by using coalescents that are able to promote the interaction into the resin particles, promoting the formation of a homogenous and resistant film.
There are two main categories of polish formulations: household polishes and institutional polishes. The difference between those two main polish formulations is the content of solids, which is higher in the case of institutional formulations.
On the other side, after certain time of use, it is necessary to remove the polish layers from the floor and apply new ones, in order to guarantee the integrity of the film, as well as its properties, already mentioned above.
Since it is quite difficult to remove the polish film without damaging the floor, especially when several layers of polish have been applied, specific polish removing formulations have been proposed in the market.
Polish remover formulations are water-based formulations usually containing surfactants, solvents, co-solvents (isopropyl alcohol), alkaline agents (Ethanolamine, NaOH) and fragrance.
The solvent contained in these polish remover formulations is important in the final application of this type of product because it impacts directly on polish remover performances, ease of use, toxicity and odor of the formulation.
Solvents are also of fundamental importance in formulations of this type, because it is the responsible to solubilize the resins present into the polish, helping the removing of it together with water and surface active agents present on the formulation.
Generally the solvent used in this application is a glycol based solvent like butyl glycol (ethylene glycol butyl ether). However, this solvent is used in a large amount in this kind of formulations, generally above 5% by weight of the polish remover composition for household polish remover, and above 25% by weight of the polish remover for institutional polish removers. In addition, butyl glycol presents the following drawbacks: it is from petrochemical source, it has strong ether-like odor, is combustible, high carbon footprint and it is harmful to humans.
In view of the above, it remains a need in the art for new solvents that are more efficient in removing polish films (in other words at lower concentrations) while offering a favorable combination of water solubility, volatility, toxicity, low odor, environmental profile and cost.
In addition, since many polish remover formulations are maintained at basic pH, there is a need for solvents that are chemically and thermally stable under basic conditions.
Further, there is an increasing need for “bio-sourced” solvents that can be used as replacements for petroleum-sourced solvents. Few bio-sourced solvents that are available can meet the increasingly demanding technical requirements for polish remover formulations. Even where such bio-sourced solvents are available, they can have various drawbacks. For example, d-limonene, which has been used as a replacement for chlorinated solvents in degreasing applications, has a strong odor, is combustible, and is classified as an irritant and sensitizer. Similarly, ethanol is a versatile solvent that is readily available from bio-based sources, but its high flammability limits its use in solvent applications. A further drawback of these solvents is that the chemical and physical properties of the solvents can only be adjusted to a limited extent.
There accordingly remains a need in the art for alternative solvents for polish remover formulations, in particular bio-sourced solvents that offer an advantageous combination of polish solubilization activity, stability under basic conditions, low odor, volatility, toxicity, environmental profile, and cost.